1. Field of the Invention
The present invention relates to a silver halide light-sensitive material and, more particularly, it relates to a silver halide light-sensitive material in which fog occurs to a lesser extent.
2. Description of the Prior Art
As a method for rapidly processing light-sensitive materials, it is known to develop at an elevated temperature. In recent years, this method has been applied to the processing of various light-sensitive materials with some success. However, in general, development of light-sensitive materials at an elevated temperature tends to cause fog, which deteriorates the quality of the photographic images. (The term "elevated temperature" as used herein means a temperature of at least about 30.degree.C.) In particular, when a developer containing a substance which has a hydrophilic colloid hardening action, for example, glutaraldehyde, etc., such as when a commercially available developer for rapidly processing X-ray films is used, films sometimes are fogged to a great extent by the developer, especially when the developer is exhausted or fatigued (i.e., when the amount of films processed approaches almost the limit of the processing capability of the developer).
In general, the photographic sensitivity of a photographic silver halide emulsion is enhanced by a sulfur compound, a reducing agent, a noble metal or a polyalkylene oxide compound. However, these sensitizing methods increase the fogging tendency as well as the photographic sensitivity. Therefore, various anti-fogging agents are added to photographic emulsions.
Typical examples of anti-fogging agents are 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene and 1-phenyl-5-mercaptotetrazole. The former compound markedly supresses increased fogging of light-sensitive materials or photographic emulsions during storage. However, this compound exhibits less of an anti-fogging effect in controlling fog immediately after the production of the light-sensitive material. On the other hand, the latter compound controls fog immediately after production. Therefore, favorable results are obtained by using these two compounds in combination.
However, when light-sensitive materials are processed at an elevated temperature, 4-hydroxy-6-methyl-1,3,3a,7-tetra-azaindene does not exhibit a marked fog controlling effect, while 1-phenyl-5-mercaptotetrazole, when used in a sufficient amount to control fog, deteriorates the sensitivity to such a marked degree that the use of this compound is not practical.
Thus, in elevated temperature development, it has been difficult to control fogging sufficiently using the aforesaid anti-fogging agents to the same extent as in ordinary development (such as is conducted at about 20.degree.C).